The present invention relates generally to a transformer power supply module and, more particularly to securement of two piece transformer cores within a transformer power supply positioned on a circuit board.
Transformer power supply modules are becoming more widely utilized for electronic communication devices such as high power radio bases, as well as for other electronic devices. These transformer power supply modules are mounted to a circuit board.
These transformer power supply modules include transformer core plates that are mounted to a circuit board, which typically carries electronic circuits. The transformer core plates are typically two metallic core plates often constructed of ferrite material. Each core plate is positioned one on each side of the dielectric or ceramic circuit board. The core plates are in contact with each other through an opening provided in the circuit board.
The circuit board in these assemblies is secured to a carrier such that one of the two metallic core plates is positioned interposed between the bottom side of the circuit board and the carrier. The other core plate is positioned overlying the circuit board. Thus, a sandwiched or stacked arrangement is created with a core plate, circuit board, a second core plate and a carrier. Additionally, a heat sink may be secured to the core plate in this stacked arrangement.
It is important that the transformer core plates are secured together to make good contact with one another in the stacked arrangement to insure optimum operation of the transformer. Additionally the core plates need to be maintained in alignment with one another and with the circuit board in a lateral direction. Thus, for proper operation of the transformer, the core plates need to be maintained with a compressive force and lateral restraint.
To secure these two core plates together, typically, a through hole is positioned in each element of the stacked arrangement of the power supply module, including the top core plate, the circuit board, the bottom core plate and the carrier. If a heat sink were positioned on the top core plate, a through hole would be positioned in the heat sink as well. With all of these components having a through hole positioned within them, the components are sandwiched together such that the through holes are in alignment. With the through holes in alignment, a screw or threaded bolt with a nut can be positioned through the through holes securing all of the components together. Alternatively, through holes may be positioned only in the carrier with bolts projecting upward through the holes. A metal clamp having through holes corresponding to the holes in the carrier is then positioned atop the sandwiched components, engaging the upwardly projecting bolts. Nuts may then be applied to the upper ends of the bolts and tightened to force the metal clamp against the sandwiched core plates and circuit board, thus securing these components to the carrier.
As can be appreciated, this bolted stacked arrangement or sandwiched assembly of this transformer power supply is awkward and time consuming to assemble. The core plates must be positioned on either side of the circuit board. The through holes of all of the components including the circuit board, the plates, the carrier and even possibly a heat sink, must be placed in registration with one another in order to engage the through holes of all of the components with a screw or bolt.
This construction makes it also difficult to test the core plates before they are installed into operation. The core plates which are positioned on either side of the circuit board are not easily maintained in alignment and secured contact with one another and must be temporarily secured together for testing prior to installation to a heat sink platform. Typically, a clamp, tape or glue would be needed to temporarily secure the top core plate, the circuit board and the bottom core plate together in order to test the core assembly. During testing, the components of the assembly must be maintained in lateral alignment and secured compressively together. After the testing, the assembly would have to be disassembled and the process of aligning and securing the components together would be repeated prior to operational use in the field.
Moreover, the individual pieces of this stacked arrangement of the power assembly module make it difficult for the field technicians to replace or install the assembly in the field. After the transformer plate cores have been removed from the circuit board, the field technician would find it awkward to position the two new core plates on opposing sides of the circuit board with the carrier heat sink platform positioned below the second plate and then align the all of these components including their respective through holes prior to securing them together with passing a screw or bolt through the through holes.
It is clear that, transformer power supply modules are awkward and difficult to assemble, test and utilize as a field replacement part. One generally needs to maintain the transformer core plates in alignment with one another on either side of the circuit board in alignment with the circuit board and maintain them in compressive contact with one another for optimal operation of the power supply module. In testing the core plates, the core plates likewise need to be compressively secured together on either side of a circuit board and maintained in lateral alignment for proper testing when testing them apart from an operational field unit. In addition, the core plates must be easily installed with compressive and lateral securement in the field for them to be used as replacement components in a field unit. Aligning through holes of multiple components can be tedious, time consuming and difficult, for assembling, testing and using as replacement components.
Additionally, the lateral alignment and restraint of the two core plates is critical when projections interposed between the core plates make electrical connection therebetween. With multiple projections involved, to make contact with the core plates, tolerances of fabrication are of concern in both plate constructions. Failure to make good contact with the other core plate will result in improper performance of the transformer. The inadequacies that may be created by inaccurate tolerances of the projections are not compensated for with a rigid securement of a clamp or screw or bolt used to connect the core plates together.
Thus, a need exists for an improved securement of the core plates of the transformer power transformer module. The improved securement must accommodate ease in assembly of the core plates to the circuit board, ease in testing the power module before sending it to the field and ease in installation for purposes of use in connection as a field replacement part. Moreover, the securement must assist in providing good contact between the core plates where the tolerances in the fabrication of the plates have not been precisely maintained.